Despite a relentless unemployment crisis, $16 trillion national debt and controversy over US handling of Middle East policy, polls indicate that a majority in this most crucial of battleground states are, indeed, prepared to give Mr Obama a second term.

Mr Romney's support appears to be slipping away. CBS on Wednesday put him ten percentage points behind the President in Ohio, a day after Romney aides tried to dismiss an ABC survey showing an eight-point deficit as an inaccurate outlier.

It is the autumn of the 65-year-old former Massachusetts governor's second bid for the White House – and on a three-day bus tour through Ohio this week, decay seemed to be setting in.

Showering attention and some $43 million on this perennial Midwestern bellwether of 11.5 million people, which no Republican has become president without winning, has earned him a rise in support of just half a percentage point since he set out a year ago. Skies are just as bleak in Florida, another must-win.

Increasingly anxious Republicans are pointing to Wednesday's first televised presidential debate in Colorado as Mr Romney's last opportunity to dramatically change the weather.

"I believe that after the debates, and after the campaigns, and after all the ads are over, the people of Ohio are going to say loud and clear on November 6 that we can't afford four more years, and we must do better," he assured supporters yesterday.

Yet with Ohio's 7.2 per cent joblessness bettering the national 8.1 rate after Mr Obama's bail-out of the region's automotive industry, many people in this middle-class heartland tell pollsters they trust the President – rather than his challenger, who opposed the rescue – to deliver that brighter day.

"Obama has a lot of rhetoric that resonates with people here," conceded Glenn Peyton, a 31-year-old Romney campaigner from Gahanna. "People are working several jobs to survive. And when you're in a bad place, and you see this guy who has done very well, it's just human nature to be wary".

The private equity career that made Mr Romney his $250 million fortune was attacked through summer by the Obama campaign as proof that he was the sort of heartless corporate raider who laid off voters' fathers or neighbours.

Even the Republican's aggressive bid to agitate sacked workers by painting Mr Obama as soft on China, the enemy stealing their jobs via currency-manipulation, has been neutralised. At Bain Capital, Mr Romney was the "outsourcer-in-chief" who sent US jobs overseas, retaliation advertisements say.

"And then," added Mr Peyton, "there is the videotape". Secretly-recorded footage of Mr Romney telling wealthy donors that 47 per cent of Americans were government-dependent "victims", refusing to take responsibility for their lives, appeared to have done still more damage.

Among that 47 per cent who pay no federal income tax are students, serving troops and military veterans. "When Romney goes on about America's freedom, he ought to remember who secured it," said Gary Frueh, a 64-year-old Vietnam veteran from Lima supporting Mr Obama.

"By getting an education, we are trying to become Americans who can take responsibility for own lives," said John Curiel, a 20-year-old politics undergraduate at Ohio Northern University.

Mr Romney's clumsy handling of the blue-collar vote was highlighted by his own running mate. At a Cincinnati steel mill, Paul Ryan moved with ease from quoting Jefferson to discussing the day's water-cooler issue – the incompetent stand-in referees drafted in to break a strike in the National Football League.

"Give me a break!" Mr Ryan said, hours after his beloved Green Bay Packers were robbed of victory in the closing seconds. Deftly comparing the "replacement refs" to Mr Obama, he added: "If you can't get it right, it's time to get out!"

By contrast, Mr Romney – who once tried to prove interest in the sport by pointing out that the owners of NFL teams were friends of his – struggled when asked about the strike in a television interview. "I'd certainly like to see some experienced referees come back on to the NFL playing fields," he said, laughing nervously.

The vice-presidential candidate, a hardscrabble native of nearby Wisconsin, is working tirelessly to stop the rot. "I like Ryan more than Romney, actually," said Patricia Murray, a supporter riding a bus to the steel mill. "He's more of an all-American dad. And he seems like a really nice guy." His mix of folksy enthusiasm and apocalyptic PowerPoint presentations on the future of US debt have converted some. "America's retreat from the leadership of the free world will put us all in danger," said Barry Silver, a 60-year-old laid-off nursing home worker who had campaigned until recently for Mr Obama.

However there is only so much that the deputy can do. Such is the concern about the effects of a Romney defeat on the 42-year-old's career that one Republican strategist this week told reporters that to run for national office again, Mr Ryan would need to "wash the stench of Romney off of him." With few paths to victory without Ohio's 18 electoral college votes, Mr Romney faces an emergency. Some 30 per cent of Ohioans, who may vote in person from Tuesday, are expected to vote before Election Day.

"Governor Romney is behind here," Mike DeWine, Ohio's Republican Attorney General and former Senator, admitted to The Daily Telegraph. "But once he gets on to that debate stage and into people's living rooms, they're going to change their minds. There is still time". Forty days – and counting.